Time-limit device for controllers.



PATENTED NOV. 21, 1905.

A. GHURGHWARD.

TIME LIMIT DEVICE FOR CONTROLLERS.

Invenor APPLIGATION FILED OUT. 10, 1903.

WLtnasscs lfi'xandmchurchwarcL UNITED STATES PATENT OFFICE.

ALEXANDER CHURCHWARD, OF NEW YORK, N. Y., ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

TIME-LIMIT DEVICE FOR CONTROLLERS.

Specification of Letters Patent.

Patented Nov. 21, 1905.

Application filed October 10, 1903. Serial No. 176,458.

To (LZZ whom, it may concern.-

Be it known that I, ALEXANDER CHURCH- WARD, a citizen of the United States, residing in the city, county, and State of New York, have invented certain new and useful Improvements in Time-Limit Devices for Controllers, of which the following is a specification.

This invention relates to controllers for electric motors, and especially those used on antomobiles where the motor takes current from a storage battery.

A great deal of the trouble with automobile-batteries has been due to lack of care in throwing on the current and not giving the motor time enough to accelerate properly. IVhen starting from a position of rest, an acceleration at the rate of one and a half miles per hour for each second of elapsed time is rapid enough, giving a speed of seven and a half miles per hour at the end of five seconds. If, however, the controller is thrown over to the full-speed position in one second, the current will rise to an abnormal value and tend to injure the battery. This is very liable to happen when starting on an upgrade or going through heavy roads or if an attempt is made to start with the brakes on.

My invention aims to prevent this trouble and render it impossible to turn on full power suddenly.

To this end it consists in a time-limit device of special construction regulating the speed at which the controller-handle can be moved. I am aware that it has been proposed to apply a dash-pot to a controller for this purpose, and I do not claim such a construction, broadly.

The particular features of novelty in my invention are hereinafter set forth, and pointed out in the claims annexed to this specification.

The accompanying drawing is a diagrammatic representation of my invention as applied to'an automobile.

The motor 1 is supplied with current from a storage battery 2, the circuit being controlled by a starting-rheostat3, having a pivoted switch-lever 4:. A piston-rod 5 is pivoted to the lever and carries a piston 6, fitting in a dash-pot cylinder 7, to which air is freely admitted at one end around the rod 5. The

other end of the cylinder is closed save for certain valves, one of which, 8, keeps normally open, preferably by gravity, the amount of opening being adjustable, preferably by a nut 9, working on a screw-threaded valvestem 10, which passes through a hole in a bracket 11. By adjusting this valve the speed at which the piston can be forced into the cylinder is varied, and thus the rate at which the resistance is cut out of the motor-circuit by the switch-lever is similarly varied.

In addition to the valve 8 there is another valve 12 kept normally open by suitable means, such as a spring 13. The movable core 14: of a solenoid 15 is arranged to actuate said valve, being preferably attached directly to the valve-stem. The solenoid is in circuit with the starting-rheostat, the motor, and battery, so that it is energized by the batterycurrent when the motor is started. So long as the acceleration is not too rapid the strength of the solenoid is not suflicient to overcome the tension of the spring 13; but if the switch-arm is moved too rapidly the corel l is actuated, closing the valve and retarding the movement of the piston by restricting the escape of air to the port controlled by the valve 8. It often happens, however, that it is necessary to start very quickly to, avoid an accident. This contingency is provided for by an extra valve 16, normally closed, as by the compression-spring 17, but capable of being opened by suitable means under control of the operator, such as a solenoid 18, whose core 19 is connected with the stem of said valve, the solenoid being in circuit with a small battery 20 and a normally open spring push-button 21 convenient to the foot of the operator. By pressing the button the valve 16 will be opened and an extra outlet from the cylinder provided of suflicient size to permit a rapid movement of the piston.

It is of course undesirable to turn on the current while the brakes are on. In order to prevent such an improper use of the controller, the circuit of the solenoid 18 may be carried through contacts 22, which are normally bridged by a contact 23 on the brake-lever 24. When the brake is set by pressing on the upper end of said lever, the contact 28 is removed from the contacts 22, thereby breaking the circuit of the solenoid 18, so that the valve 16 cannot be opened so long as the brakes are on. As an additional safeguard the brake-rod is connected with a lever 26, which when the brakes are set closes the valve 8. This leaves only the valve 12 open, and as this will be closed by the abnormal rush of current into the stationary motor When the I switch-lever has cut out a little of the rheostat the piston is almost immediately stopped and no more resistance can be cut out. The invention therefore affords an efficient and fool-proof controller, with provisions for emergency operation when necessary. The dash-pot is set for a minimum time limit by the two open valves 8 and 12. This time limit will be automatically increased by the closing of the valve 12 when current is turned on so fast as to exceed a predetermined safe strength. The time limit can be decreased momentarily or for a longer period by the operator by closing the circuit of the solenoid 18 and opening the valve 16. If the brake is left on, the valve 16 cannot be opened, the valve 8 is closed, and the valve 12 Will be closed before the current-flow can become great enough to injure the battery.

In accordance with the patent statutes I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

WV h at I claim as new, and desire to secure by Letters Patent of the United States, is

1. The combination with a controller-ham dle, of a dash-pot set for a minimum time limit, and means for automatically increasing said time limit if said handle is moved too quickly.

2. The combination with a controller-handle, of adash-potand two normally open valves thereon, one of which closes under a predetermined excess of current.

3. The combination with a controller-handle, of a dash-pot, an adjustable valve thereon, a solenoid responsive to an excess of current, and a valve on the dash-pot adapted to be closed by said solenoid.

4. The combination with a controller-handle, of a dash-pot set for a determined time limit, manually-controlled means for decreasing said time limit at will, and means for antomatically restoring the determined, time limit when the manual controlling influence ceases.

5. The combination with a controller-handle, of a dash-pot, anormallyopen valve thereon, a normally closed valve, said valves controlling independent passages and means under the control of the operator for opening said closed valve.

6. The combination with a controller-handle, of a dash-pot, a normally open valve thereon, a normally closed valve, and electromagnetic means for opening said closed valve, including a circuit-closer under control of the operator.

7. The combination with a controller-handle, of a dash-pot set for acertain time limit, a brake, and means whereby said time limit is increased if the brake is left on.

8. The combination with a controller-handle, of a dash-pot, anormallyopenvalve thereon, a brake, and means for closing said valve when the brake is applied.

9. The combination with a controller-handle, of a dash-pot, a normally open valve thereon, a lever for closing said valve, a brake-rod, and connections between said rod and lever.

10. The combination with a controller-handle, of a dash-pot, a normally closed valve thereon, means for opening said valve at will, a brake, and means for preventing the open ing of said valve when the brake is on.

11. The combination with a controller-handle, of a dash-pot, a normally closed valve thereon, electromagnetic means for opening said valve, a brake, and means for opening the circuit of the electromagnet when the brake is applied.

12. The combination with a controller-handle, of a dash-pot set for a certain time limit, means for increasing said limit and automatically restoring it, and means for decreasing said limit.

13. The combination with a controller-handle,ofadashpot for acertain timelimit, means for automatically increasing said limit if current is turned on too fast, and means for decreasing said limit at the will of the operator.

1 1. The combination with a controller-handle, of a dash-pot set for a certain time limit, means for automatically increasing said limit if current is turned on too fast, means for decreasing said limit momentarily at will, a brake, and means whereby said limit is very greatly increased if the brake is left on.

15. The combination with a controller-handle, of a dash-pot set for a certain time limit, means for decreasing said limit at the will of the operator, and means for rendering said decreasing means inoperative if the brake is left on.

16. The combination with a controller-handle, of a checking device therefor set for a minimum time limit, and means for automatically increasing said time limit if the handle is moved too quickly.

17. The combination with a controller-handle, of a checking device therefor set for a minimum time limit, and means for automatically increasing said time limit under a predetermined excess of current.

18. The combination with a controller-handle, of a checking device therefor, means for automatically setting said checking device for a predetermined time limit, and means for decreasing said time limit at will.

19. The combination with a controller-handle, of a checking device therefor, means for automatically setting said device for a predetermined time limit, and means for increasing said time limit at will.

20. The combination with a controller-handle, of a checking device therefor set for a dle, of a checking device therefor, means for certain time limit. means for automatically inautomatically setting said device for detercreasing said limit and automatically restormining the time limit, and means for varying ing it, and means for decreasing said limit 5 5 said time limitat Will. and automatically restoring it.

21. The combination with a controller-han- In Witness whereof I have hereunto set my dle, of a checking device therefor set for a hand this 7th day of October, 1903. certain time limit, means for increasing said ALEXANDER CHURCHVVARD. limit, and means for automatically decreasing Witnesses:

I said limit. 4 l M. L. CoFFIN,

22. The combination with a controller-hanl E. D. EVANS. 

